Add a Gitlab::Git::Env to store Git-specific env thread-safely

Signed-off-by: Rémy Coutable <remy@rymai.me>

1 files changed, 38 insertions, 0 deletions

diff --git a/lib/gitlab/git/env.rb b/lib/gitlab/git/env.rb
new file mode 100644
index 00000000000..0fdc57ec954
--- /dev/null
+++ b/lib/gitlab/git/env.rb
@@ -0,0 +1,38 @@
+module Gitlab
+  module Git
+    # Ephemeral (per request) storage for environment variables that some Git
+    # commands may need.
+    #
+    # For example, in pre-receive hooks, new objects are put in a temporary
+    # $GIT_OBJECT_DIRECTORY. Without it set, the new objects cannot be retrieved
+    # (this would break push rules for instance).
+    #
+    # This class is thread-safe via RequestStore.
+    class Env
+      WHITELISTED_GIT_VARIABLES = %w[
+        GIT_OBJECT_DIRECTORY
+        GIT_ALTERNATE_OBJECT_DIRECTORIES
+      ].freeze
+
+      def self.set(env)
+        return unless RequestStore.active?
+
+        RequestStore.store[:gitlab_git_env] = whitelist_git_env(env)
+      end
+
+      def self.all
+        return {} unless RequestStore.active?
+
+        RequestStore.fetch(:gitlab_git_env) { {} }
+      end
+
+      def self.[](key)
+        all[key]
+      end
+
+      def self.whitelist_git_env(env)
+        env.select { |key, _| WHITELISTED_GIT_VARIABLES.include?(key.to_s) }.with_indifferent_access
+      end
+    end
+  end
+end